Inter is the workhorse typeface of 2020s SaaS — Linear, Notion, Figma, Mozilla, GitHub, and dozens more use it as their primary family. Its narrow apertures and rationalist proportions render cleanly at 12-14px, where Helvetica and Arial muddle. Inter Variable ships an entire weight axis in a single file, enabling custom weight ladders (Linear runs 400/510/590, not the standard 400/500/600).
Glossary · typography
Inter
Rasmus Andersson's open-source sans-serif typeface, optimized for UI rendering at small sizes — the de-facto default for SaaS interfaces.
External reference
Rsms — InterCatalogued examples
3 catalogued sites demonstrate inter in production.